It's not that hard. I'm not an expert on Dark Souls, but I played it at some friend's and I found it much easier than Sekiro (which I played from A to Z and I loved it). You can have ranged attacks with Dark Souls which is not the case in Sekiro (except for the Shurikens, but they're pretty week). In Sekiro, you either use your katana or you die
Anyway, I like the fact that these games are not super easy. They give you challenges that make you learn and progress. It's better than games where you just have to smash the attack button.
I feel that Sekiro is just like music, each ennemy has their own rhythm, you just have to find it and follow it. Since you don't have the partition, you just have to listen and find it. It really reminds me of Japanese martial arts teachings.
If you want to start a game from "From Software", you have to be persistant, watch and learn by yourself. Then, when you master the technique (you will, eventually), the game becomes thrilling and orgasmic (that's an understatement BTW )
The biggest scam of all times.